London - Romelu Lukaku was only fit enough to be named among Manchester United's substitutes for their FA Cup final clash with Chelsea on Saturday.

Lukaku had missed the previous three matches after suffering an ankle injury against Arsenal in April and United manager Jose Mourinho decided the Belgium striker wasn't ready to start at Wembley.

England forward Marcus Rashford took Lukaku's place in the United starting line-up, with Alexis Sanchez and Jesse Lingard offering support in a three-man attack.

"We change Romelu with Marcus Rashford. He is going to play in the same position but, obviously, with different qualities," Mourinho said.

Lukaku's absence is a blow to United's hopes of winning the FA Cup for a record-equalling 13th time.

Since former Chelsea star Lukaku was sidelined, United have lacked a cutting edge and they scored only once in their last three games of the season.

The 25-year-old had energised United with a goal spree at the start of the campaign after arriving from Everton in a 75 million ($101 million) deal.

Lukaku has scored 27 times for United in all competitions this season, making his first season at Old Trafford a success overall.

David De Gea started in goal for United despite only playing in the semi-final of the competition this season as Mourinho didn't believe his understudy Sergio Romero was fit enough to feature.

Paul Pogba was alongside former Chelsea ace Nemanja Matic in United's midfield.

For Chelsea, France striker Olivier Giroud started up front in place of the out-of-form Alvaro Morata.

Thibaut Courtois made his first FA Cup appearance this season, starting in goal instead of Willy Caballero.

Despite a disappointing first season with Chelsea, Tiemoue Bakayoko featured in midfield alongside Cesc Fabregas and N'Golo Kante.

Teams:

Chelsea

Thibaut Courtois, Cesar Azpilicueta, Gary Cahill, Antonio Rudiger, Victor Moses, Cesc Fabregas, N'Golo Kante, Tiemoue Bakayoko, Marcos Alonso, Eden Hazard, Olivier Giroud

Manchester United

David De Gea, Antonio Valencia, Chris Smalling, Phil Jones, Ashley Young, Ander Herrera, Nemanja Matic, Paul Pogba, Jesse Lingard, Marcus Rashford, Alexis Sanchez

Referee: Michael Oliver